This invention relates to the efficient packaging of mass memory units (such as hard disk drive arrays) and, more particularly, to a mass memory unit incorporating a cabinet with one or more drawers which can be individually opened to provide access to a vertically disposed array of mass storage devices.
Large scale computer systems incorporate banks of mass storage units such as arrays of hard disk drives. In the prior art mass storage units, disk drives in servers or disk subsystems are usually packaged in canisters which permit manipulation of the disk drives including the support of hot plug/unplug functions. The canisters each have a connector adapted to engage a complementarily configured connector on a backplane or a midplane which includes printed circuit traces conventionally interfacing the disc drives with system circuitry. Each canister is individually shielded to limit RFI/EMI radiation to within required minimum levels. Alternatively, a shielded door is used to enclose a bank of canisters. If no active canister is plugged into any available position, it is necessary to insert a dummy canister into that position in order to maintain acceptable radiation levels and also to prevent disturbance of the cooling airflow pattern.
Users of large scale computer systems wish, on an ongoing basis, to have access to mass storage units with features which exceed the capabilities and potential of the prior art mass storage units. Among these desired features is packaging which anticipates technology evolution and which offers very high reliability and high availability at relatively low cost. More particularly, what is desired is a mass storage unit with high reliability specifications, a high storage capacity per cubic meter, excellent cooling airflow management, technology anticipation, ready functional integration with available controllers, modularity, accommodation of disk drives having different form factors and excellent compliance with RFI/EMI regulations, all at a competitive price. The present invention is directed to a mass storage unit which achieves all these aims and provides still further advantages.
Briefly, these and other aims of the invention are achieved by a mass memory storage unit which includes a cabinet and one or more drawers incorporated into the cabinet. Each drawer is movable between closed and open positions to permit access to the interior for service. Inside each drawer, there is a connector plane disposed generally to one side of the drawer interior and parallel to the direction of travel between the closed and open positions. The connector plane incorporates a plurality of connectors for receiving storage devices (for example, hard disk drives), each incorporating a connector complementarily configured to mate with one of the connectors on the connector plane. Thus, each storage device is individually removable. Support and interface devices are coupled to the connector plane by suitable complementary connectors. It is useful to provide a cable, which itself may be detachable from the connector plane, to establish a redundant connection such that the devices in a drawer remain in-circuit when that drawer is opened for access to the enclosed components.